MICROSATELLITES IN MALUS X DOMESTICA (APPLE) - ABUNDANCE, POLYMORPHISM AND CULTIVAR IDENTIFICATION

Screening of an apple genomic library with (GA)15 and (GT)15 probes de monstrated that these repeats are abundant, occurring about every 120 and 190 kb, respectively. Microsatellites isolated from a small insert library enriched for (GA) repeats contained numbers of repeats rangin g from 7 to 39. Primers to these microsatellite loci were able to dire ct the amplification of the repeats in 21 different cultivars. The maj ority of markers were highly polymorphic, diploid, and showed simple M endelian inheritance, although about 25% of markers generated complex banding patterns consistent with the amplification of more than one lo cus. As few as three microsatellite markers were sufficient to differe ntiate between all 21 cultivars.